Bill Sutherland

The Structure of Integrable One-Dimensional Systems (2007)

Sutherland, Bill

We explain the relationship between the classical description of an integrable system in terms of invariant tori and action-angle variables, and the quantum description in terms of the asymptotic...

Bandgap Extremization: Some Exact Results (2001)

Paul, Prabasaj, Sutherland, Bill

We present here a variational method for maximizing the bandgap in a one-dimensional system where the potential is subject to given constraints. Two specific examples are studied in detail. In the...

Conservation laws in the continuum $1/r^2$systems (1996)

Rudolf, Romer A, Shastry, Siriam B, Sutherland, Bill

We study the conservation laws of both the classical and the quantum mechanical continuum $1/r^2$ type systems. For the classical case, we introduce new integrals of motion along the recent ideas of...

Conservation laws in the continuum $1/r^2$systems (1996)

Rudolf, Romer A, Shastry, Siriam B, Sutherland, Bill

We study the conservation laws of both the classical and the quantum mechanical continuum $1/r^2$ type systems. For the classical case, we introduce new integrals of motion along the recent ideas of...

Exact Solution of a One-Dimensional Multicomponent Lattice Gas with Hyperbolic Interaction (1994)

Sutherland, Bill, Römer, Rudolf A., Shastry, B. Sriram

We present the exact solution to a one-dimensional multicomponent quantum lattice model interacting by an exchange operator which falls off as the inverse-sinh-square of the distance. This...

Transport Properties of a One-Dimensional Two-Component Quantum Liquid with Hyperbolic Interactions (1994)

Römer, Rudolf A., Sutherland, Bill

We present an investigation of the sinh-cosh (SC) interaction model with twisted boundary conditions. We argue that, when unlike particles repel, the SC model may be usefully viewed as a...

Exact Derivation of Luttinger Liquid Relation in a One-Dimensional Two-Component Quantum System with Hyperbolic Interactions (1994)

Römer, Rudolf A., Sutherland, Bill

We present an exact calculation of the Luttinger liquid relation for the one-dimensional, two-component SC model in the interaction strength range $-1

Critical Exponents for the SC-Model in the Zero Sector (1993)

Römer, Rudolf A., Sutherland, Bill

In this paper, we continue our investigation of a one-dimensional, two-component, quantum many-body system in which like particles interact with a pair potential $s(s+1)/{\rm sinh}^{2}(r)$, while...

Exiton, Spinon and Spin Wave Modes in an Exactly Soluble One-Dimensional Quantum Many-Body System (1993)

Sutherland, Bill, R"omer, Rudolf A.

In this paper, we present the exact solution to a one-dimensional, two-component, quantum many-body system in which like particles interact with a pair potential $s(s+1)/{\rm sinh}^{2}(r)$, while...

Conformal Invariance in Periodic Quantum Chains (1993)

R"omer, Rudolf A., Sutherland, Bill

We show how conformal invariance predicts the functional form of two-point correlators in one-dimensional periodic quantum systems. Numerical evidence for this functional form in a wide class of...

Solution of Some Integrable One-Dimensional Quantum Systems (1992)

Sutherland, Bill, Shastry, B. Sriram

In this paper, we investigate a family of one-dimensional multi-component quantum many-body systems. The interaction is an exchange interaction based on the familiar family of integrable systems...

Super Lax Pairs and Infinite Symmetries in The $1/r^2$ System (1992)

Shastry, B. Sriram, Sutherland, Bill

We present an algebraic structure that provides an interesting and novel link between supersymmetry and quantum integrability. This structure underlies two classes of models that are exactly solvable...

Test of Conformal Invariance in One-Dimensional Quantum Liquid with Long-Range Interaction (1992)

R"omer, Rudolf A., Sutherland, Bill

We numerically study the momentum distribution of one-dimensional Bose and Fermi systems with long-range interaction $g/r^2$ for the ``special'' values $g= -\frac{1}{2}, 0, 4$, singled out by random...

Completely integrable systems and groups generated by reflections

Gutkin, Eugene, Sutherland, Bill

We introduce a class of quantum Hamiltonian systems with δ-function potential, related to groups generated by reflections. They generalize the system of equal elastic particles on the line. We show...

Completely integrable systems and groups generated by reflections

Gutkin, Eugene, Sutherland, Bill

We introduce a class of quantum Hamiltonian systems with δ-function potential, related to groups generated by reflections. They generalize the system of equal elastic particles on the line. We show...